Internet History Sourcebooks Project
Fordham University: Medieval Sourcebook: Hildegard Von Bingen (1098 1179 Ce)
This site from the Fordham University provides a detailed biography of this remarkable woman includes information about her writing, her health (she apparently suffered from migranes), her music, and her religious beliefs. A bibliography...
Stanford University
Stanford University: Medieval Music Birth of Polyphony
An article on the beginning of Polyphonic music during the Middle Ages. You'll also find illustrations.